As fuel cell power plants are being integrated into useable vehicles, developing efficient ways of supplying the fuel needed to operate the fuel cell stack becomes more critical. Hydrogen gas is the common fuel input to the stack and may be stored on-board in suitable tanks. While pure hydrogen gas is an efficient fuel, storing it on-board a vehicle has drawbacks related to packaging and mass.
As an alternative to storing pure hydrogen gas on-board a vehicle, other fuels such as gasoline or methanol may be stored on-board and processed through a reformer to convert the fuel to reformate comprising hydrogen, carbon dioxide, carbon monoxide, and water vapor. The reformate may be passed through a shift converter and gas purifiers to remove carbon monoxide before delivering the hydrogen to the fuel cell stack. This complete reformation process is not only complex to engineer, but consumes valuable packaging space and mass.
A further consideration in designing a vehicle powered by an electrochemical engine is how to manage the heat produced by the electrochemical reaction in the fuel cell stack. The stack may produce waste heat ranging in temperatures from 80.degree. C. to 100.degree. C. If a traditional thermal management system including a radiator is employed, the radiator will require significant surface area to meet the demands of the electrochemical engine and will be impractical for a commercial vehicle.